Multiple cartridge launcher



Get. 25, 1949. g, K N 2,485,601

MULTIPLE CARTRIDGE LAUNCHER Fild Sept. 26, l947 4 Sheets-Sheet 2 E1 E11"ETLBE N; Hickman Oct. 25, 1949. c. N. HICKMAN uunwrrnn CARTRIDGELAUNCHER Filed Sept. 26, 1947 4 Sheets-Sheet 3 E131" ET'ICE N-Hickman1%. M wkawflb Oct, 25, 1949. c. N. HICKMAN MULTIPLE summer: LAUNCHER 4Sheets-Sheet 4 Filed Sept. 26, 1947 sum EH E Q V n lll EIETETIEE N Hi|:]man Slim Patented Oct. 25 1949 UNITED STATES PATENT OFFICE resented bythe Executive. Secretary of the ffice of Scientific Research, and.Development Applicationls eptember 26,1947, Serial N o. '17 6,391

3 Claims. (Cl. 244-453) (Granted. under. the act of March- 3, 1883, as

amended. April 30, 1928; 370 0.: G. 757) The invention described hereinmay bemanufactured and used by the Government for gov ernmentalpurposeswithout the payment of any royalty thereon.

This invention relates to a launching device for rocket projectiles, andin particular for winged rockets of the type having a wing loading toogreat for self-launching due to the inability to obtain, by jetpropulsion alone, a speed greater than its stalling speed. In such acase external power must be lent for the take off..

Such devices, broadly, have been known and used, and in particular,rockets have been powered for take on by the use of concentratedhydrogen peroxide in the catapult.

The present invention is concerned; with, a method and means forcatapulting' missiles wherein a conventional propellant, such assmokeless powder, is employed, and the necessary energy is suppliedstepwise as the missile proceeds along the launcher, the release ofenergy being occasioned by the missile itself in. passage.

It is, therefore, an object of' the invention to provide a launchingdevice wherein propulsive energy is supplied in increments, furtherobjects being to provide novel means for communicating propulsive energyin a launching tube to-an external projectile, utilizing availableenergy to the maximum degree and with optimumacceleration performance ofthe projectile.

To these and other ends, reference, is had to the accompanyingspecification and claims, and. to the drawings, in which:

Fig. 1 is a side view of a launcher with rocket in place,

Fig. 2 is a top plan view of Fig. 1 without the rocket,

Fig. 3 is a section taken on the line 3-3 of Fig. 2,

Fig. 4 is a section taken on the. line. 4-4 of Fig. 3,

Fig. 5 is a section taken on the, line, 55 of Fig. .3,

Fig. 6 is a section taken on the line. 6-6 of Fig. 3,

Fig. '7 is a side view in partial axial section of an electricallyactuated cartridge and holder,,

Fig. 8 is a section taken on the line 8-8 of Fig. '7,

Fig. 9 is a side view in partial axial section of a percussioncartridge. and holder,

Fig. 10 is a longitudinal section of alauncher withmodified sealingmeans,

Fig. 11 isa partial. end view-of Fig. 10, and

} pipe.

2 Fig. l2'is a-sectiorr taken onthe linel2 l2' of-Fig; 10.

The launcher shown comprises a mairr sup porting member I- held onstandards? of" varying height to afiord an angle of attack (or elevation) for the missile to be'launched; andhaving cross webs 3. A seriesof ribs 4 atop the member I support a' launching deck 5-andalso serveto" hold and strengthen against bursting the pressure-' tube 6.

Thedeck and tubehave'alig-ned slots Tand 8 throughout their length forcommunication from the missile, such as 9 tothe interior of thetube. Apiston. III is slidably-fitted in-the tube 6; and

has-a bore M (Fig. 3) receiving a pipe H the purpose of which is. tosealthe slot 8against escapeof gases inthe region behind the-movingpistom. The pipe is-1preliminarily held near the slot 8.by means such asa wire loop l3 andcross member ltwhichmerely rests on' the tube 6-(seeFig. 6.)

The piston Ii) carriesahook l5;which.passes= up.through. slots822.111.7111]. position toengage. a portion of the missilasuchaseye lug[6, to;

impart: motion. to the: missile. The bore Id of the. pistonis shownslanted to provide spacezon, the; front. side of. the piston for; thehook; A: sled is provided for. the missile.

Therear end of the; tube 6. is sea1ed,,asby a. plug. ll, shownthreaded.therein, and an.adjust-.- ment member is provided. to .vary theinitialmosietionof the piston. This member may: comprise a rod l8threaded through.

It, will. now be apparentthatupon develop:-

3 ment. of. pressure behind the piston,v the. latter; willprogress alongthe tube, carrying, the missile:

with it. Duringthis, movement the tubeisswept: of hangers l3, and thesealing, pipe. 12 is. laid; up against the. slot 8 whereit is retainedbythe pressure in the tube until the pistonhasbeem ejected, after which itfalls to the bottom of. the

tube. The pipe may be restrung for reuse.

In Fig. 10 is shown a modification wherein a; sealing ribbon I2 isemployed in place of the In this case the ribbon isattachedas at l9 atthe breech of the tube. It is maintained near theslot 8' by anarticulated member ill attached. to the piston of. a. pneumaticzjacls 24which servestotake upundue slack. in. the ribs ban. The operationissimilar to. the otherde.--

scribed modification except that in.lieu.of.sweep.-- ing outhangers, thepiston merely breaks; the; connection. of the tape at and rotates themember 20.

55, Withthelengthof tube. employed feet iny a given case) and relativelysmall bore, ballistic theory as expressed by the equations of motion,state, energy and burning for explosive charges cannot provide for thepropulsion of a considerable mass by a single charge. The propellingeffort is therefore accomplished by a series of charges spaced along thetube and initiated only after passage of the projectile. For the firstof these an electrically fired cartridge has been found to besatisfactory but, for all subsequent charges, percussion firing has beenfound to be of best advantage.

The electric cartridge is shown in Fig. 8. The

container 22 is screw threaded into an adapter 23 which fits in the tube6. It is closed by a cap 24 to which is attached a plastictoroidal-shaped member 25 containing an igniting composition 26 withembedded filament 27. Also in the cap is a plug contact 28 and insulator29. The contact leads tothe filament and through ground to a source ofE. M. F. The cap 24 also bears wormhead 'wires 30 which carry tubularsticks of propellant 3| as in rocket chambers. A metal plate 32 with anopening 33 acts as a partial confinement to insure good ignition of thepowder charge. A cover plate 34 to keep out moisture and dust normallyseals the opening 33 but is rupturable by the propellant. The percussioncartridge in Fig. 9 has an outer case 35 and an inner case 35', thelatter being roughly similar to the electric cartridge, but having aconventional primer tube 36 with percussion igniter 37 carried in a head38 which also carries trap wires and propellant. A plate 39 fixed in theforward end has numerous large through openings 40 normally covered by athin magnesium plate 4| held temporarily in place as by a friction fit,for which purpose it may conveniently have a flange 42. The whole innercase is slidable in the outer case against the bias of a spring 43contained in a well 44 in the head 45 of the outer case which alsocarries a fixed firin pin 46 threaded through the head for adjustabilityand having a locking nut 41.

The percussion cartridge is operated by gas pressure in the main tube 6.As the piston passes the inner end of a cartridge case, the propellentgas pressure operates on the thin plate 41 which is backed up by theplate 39. With obturation at this end, the entire inner case is urgedtoward the head 45 of the outer case and the igniter 31 is brought intofiring engagement with the point of pin 46. The propellent blast whichfollows blows the thin plate 4| into the main tube 6 and the propellentgas pressure is superimposed on the pressure already existing in thetube. Thus the timing is automatically controlled by the spacing of thecartridges along the tube.

In one successful embodiment a total projectile load of 5400 lbs. wasaccelerated to a speed of 240 miles per hour with a maximum accelerationof about 17 g in a distance of 160 feet, the maximum tube pressure being850 to 900 p. s. 1. Total ejection time was about 0.85 second.

The ballistic conditions in a launcher as described herein are radicallydifferent from those obtaining in ordinary guns where a high velocity isattained in a very short time interval. Ordinary theory is notapplicable in the launcher for two main reasons: (1) The rate of burningis not proportional to the pressures of less than 1000 p. s. i. as theyare at pressures of 30,000 p. s. i. or above found in guns, and (2) inthe launcher, powder surfaces are introduced at specific time intervals.In addition, heat losses are considerably greater in the launcher.

In the solution of the problem by entirely unconventional methods, amain objective was to obtain as nearly, as possible, a constant pressurein the launcher, and I have found that in order to accomplish this thepowder burning surface must increase linearly with time. To this end Ihave found that a single-perforated grain such as employed in rocketsand which has an almost constant burning surface had a favorable bearingon the result. Cartridges having such grains are introduced at varioustimes so that the total burning surface, although not increasing exactlylinearly with the time, il creases stepwise in such a 'way as'toapproximate a linear rate. Such increments may be distributed in largenumber with small charge and narrow spacing or with larger charge andwider spacing. It was found that six charges were suflicient, for thefoot tube employed, to give a. reasonably uniform pressure.

The charges may be introduced throughout the total time in which casemuch of the later charges will be unconsumed, and result inafter-burning, chufiing, flash and smoke. For this reason it ispreferable to introduce charges for only part of the time even thoughthis results in the pressure falling off toward the end of pistontravel. I have found that an adequate situation exists when charges areintroduced for only about one-half the total time, using a web of powderthat is completely consumed in one-half the total time.

I have further found that the weight of charges should be equal, exceptthe first, which should have half the weight of the others, and that thecharges should be spaced at intervals which in each case correspond tothe total burning of the previous charge, and I have further found thatthe piston should have an initial position leaving a clear space ofabout one foot in the rear of the tube.

The employment of a rocket-type charge in the launcher is not obvious,and it was a matter of discovery that elicited the fact that the powderwas erratic and subject to cracking and general breakup when nottrapped, and it was further found that faster ignition in the laterrounds occurred with percussion firing as compared with electricalfiring.

Having now described my invention, what I desire to claim as new andsecure by Letters Paten 1s:

1. A launcher for missiles comprising a ramp, there being a longitudinalslot in said ramp, a barrel member under said ramp and having a slotaligned with the slot in the ramp, sealing means for the slot in thebarrel member, temporary suspension means for the sealing means, apiston in said bore surrounding said sealing means and urging the sameinto sealing engagement with the barrel slot, and means on the pistonpassing through both said slots for engagement with a missile on saidramp.

2. A percussion firing cartridge comprising an outer casing having anopen end, an inner casing slidable in said outer casing and carrying apropellant charge, complementary ignition means on the respectivecasings constructed and arranged for actuation on relative sliding ofsaid casings, a spring member biasing said casings to safe relation,valve means carried by said inner casing adjacent said open end andarranged to permit gas discharge from said inner casing through saidopen end but effecting piston action of said inner casing in response tofluid pressure incident through said open end into said outer casing,said valve means comprising an end plate having an orifice and a coverplate releasably held externally of said end plate and coveringsaidorifice.

3. In a launcher for a missile, a flat elongated deck, a barrel, meansuniting and supporting "said barrel and deck in closely-spaced parallelrelation, there being a first longitudinal slot insaid barrel and asecond slot in said deck adjacent and parallel with said first slot,said slots'extending throughout the length of said decl; and barrel,respectively, a piston slidably fitting said barrel, means connectedwith said piston and extending through said slots for connectionfwith amissile slidable on and along said deck, sealing means mounted withinsaid barrel adjacent its slot for movement into sealing relationtherewith, there being a connection between said piston and sealingmeans operable to move said sealing means into sealing position inresponse to passage of said piston therealong, a plurality oflongitudinally spaced cartridge casings spaced along said barrel andcommunicating therewith, each casing adapted to contain an explosivecharge, and

5 means responsive to the passage of said piston adjacent each saidcasing to fire the same.

CLARENCE N. HICKNLAN.

REFERENCES CITED 10 The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 1 200,740 Lyman Feb. 26,18782,200,427 Merz May 14, 1940 2,360,217 Francis Oct. 10, 1944 FOREIGNPATENTS 20 Number Country Date 478,427 Great Britain Jan. 18, 1938

